Generally, a valve train of an engine employs a pushrod and a hydraulic lash adjuster to transmit motion from a rotary cam to a rocker arm of the valve train. Due to continuous operation, the pushrod may experience loosening or breakage. In such a situation, the pushrod may move from its position and may slip into a cavity of the engine such as within the engine block. As a result, the slipped pushrod may interfere with other parts within the engine causing extreme damage to the engine. For example, the pushrod may slip back into the engine block and damage one or more valves associated with a cooling/lubrication system of the engine. This may lead to coolant/lubrication leakage or contamination, resulting in machine downtime, expensive repairs, and so on.
U.S. Pat. No. 6,978,752 describes a valve lifter guide for use with an internal combustion engine. The valve lifter guide is adapted for maintaining an angular position of a reciprocable valve lifter. The valve lifter includes a circumferential surface with an axially extending alignment flat. The valve lifter guide includes a metal guide body having a longitudinal guide wall. The guide wall includes a guide opening adapted to receive a valve lifter. The valve lifter guide includes a nonmetallic insert extending laterally across the guide wall. The insert is retained by the guide body adjacent a longitudinal end of the guide opening. The insert is positioned to engage the alignment flat of the valve lifter received in the guide opening to substantially maintain the angular position of the valve lifter in the guide.
Currently used guides for the valve train may be unable to restrict slippage of the pushrod within the cavity of the engine in case of a failure thereof. Hence, there is a need for an improved system for controlling slippage of the pushrod into the engine.